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(No Model.) J. A. MALONE Y.

ELEGYTRIG TELEPHONE TRANSMITTER. No. 296,593. I Patented Apr. 8, 1884-} n'il a I x f 4 WITNESSES 4 v I.N'V'EJV'TOR flt to r ney "IRS. Phommno m her. Wasfingian. D. c,

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J. A. MALONEY. ELECTRIC TELEPHONE TRANSMITTER.

Patented. Apr. 8, 1884.

, tact-point.

SPECIFICATION forming part of Letters Patent JAMES A. luALONEY, on WASHINGTON,. DISTRIGT on co.Lmrnrn.;-

Ui iifrno STATES 'i PATENT rricn.

ELEcTRlc TELEPHONE-TRANSMITTER.

No. 296,593, dated April 8, 1884.

Application filed July 11, 1883. (No model.)

To aZZ whom it may concern.-

Be it known that I, Janus A. MALoNEY, of Washington city, in the District of Columbia, haveinvented certain new and useful Improvements in Electric Telephone-Tranemitters, of which the following is a specification.

My improvements have particular reference to a'telephone-transmitter of the type illustrated in Letters Patent No. 274,353, dated March 20, 1883, although they are in some respects susceptible of application to tra nsmitters of other types.

The inventionis directed, mainly, to an improved construction and arrangement of the contact-points through which the impulses, due to the vibrations of the diaphragm are transmitted to line, and it is characterized, principally, by the comhination,with the diaphragm, of a contactpoint, a springacting carrier therefor attached to and moving with the diaphragm, and'a controlling device-termed by me a stirrup-which bears upon the springearrier, and during the vibrations of the latter operates to direct its movements to and from the stationary contact-point in connection with which the carrier contact-point works. The organization just outlined is very efficient and sensitive in practical operation, and responds to the slightest movements of the diaphragm.

lhe nature of my invention and the manner in which the same is or may becarried into effect can best be explained and understood by reference to the accompanying drawings,

' in which- Figure 1 is a side elevation of the transmitter with the side of the box or case removed. Fig. 2 is a rear elevation of the working parts with the back of the case cut away or removed.

Fig. 3 represents on enlarged scale a cross section of the removable rear contact-point and the lower part of the stem of its carrier, together with an elevation of part of the stationary contact-point in connection with which it works. Fig. i is a plan of the movable con- Fig. 5 is a front sectional elevation on enlarged scale of the transmitter, representing diagrammatically the circuit-connections. Fig. 6 is an enlarged sectional elevation of the lower part of the carrier-stem, to be hereinafter referred to.

A is the case of theinstru ment,the front wall, A, of which is covered by the hinged door A, the voice-opening being formed through both A and A as indicated by dotted lines in Fig. l. The door A is provided to allow access to be had to the front contact-point for the purpose of adjusting it, &c. B is the diaphragm, made of a thin sheet of any proper material in this instance wood. It is attached at its top and bottom to suitable cleats or supports, a, between which and the diaphragm are inter posed buffers or cushions a. of vulcanized rubber or other suitable elastic material, for the purpose of preventing the diaphragm from being influenced by extraneous vibrations transmitted through the case A from the wall or other part to which the case is attached. On the front of the diaphragm is fixed a point or plate, 0, of conducting material-platinun1 in this instance-and opposite c is the carbon point 0, carried by an arm, 0 of spring metal, which is pressed toward the diaphragm by an adjusting-screwy? Upon the rear face of the diaphragm is another contaotpoint, designed to operate in connection with a stationary contact-point, (1, consisting in this instance of a cylinder, 41, of brass or other metal, into the top of which'is screwed or inserted a disk, (1 of platinum, which latter is the contact-point proper. The cylinder is carried by an adj usting screw-stem, (2 which screws through a metal bracket, (i and is provided with a locknut, d By this means the contact cl can be adjusted up and down with great nicety.

I now proceed to describe the contact which operates in connection with d. It maybe described in a general way as consisting of a carbon button or disk, c, (the contact-point proper,)which is supported bya bent spring acting carrier-stem, f, of metal or other good conducting matriahattached to diaphragm B. The stem,at its upper end, where it is attached to the diaphragm, is for a portion of its length horizontal. At its lower end, where the button e is, it is for a portion of its length vertical, so as to directly overhang the part d, thus allowing the button or disk 6 to make at the neoessary times square contact with the platinum disk d and its intermediate portion, f,extends diagonally between the two end portions, and is flattened,so as to in effect be a spring-strip, for the purpose about to be explained.

Under the arrangementrthus fardescribed itwilfdfi that when the diaphragm is in vibration the effect will be to move the contact e to and fro across or above the face of stationary contact (I. In order to translate this motion of contact 6 into an up-and-down movement, or a movement to and from stationary contact (1, I make use of a controlling device, or, as I have hereinbefore termed it, a stirrup, which is shown at g. This stirrup consists of a stiff strip of metal or other suitable material, which, at its upper end, is attached to the upper wooden cross-cleat or support, a, and thence extends down so that its lower end shall bear down upon the slanting sprin'gy portion f of carrier f. Thelower end of the stirrup is forked, so as to straddle the part f, and thus to guide and prevent lateral movement of the carrier; and its upper end is held to the part a bya slot and set-screw connection, f whereby the stirrup can be vertically adjusted with a view to assuring it in proper position with respectto the carrier. Under this arrangement it will be seen that the stirrup, when the carrier moves with the diaphragm, will act to depress it and permit it to rise according to the direction of its movement, thus causing contact e to have motion to and from the other contact, d. I here remark that this arrangement manifestly is applicable not only to the transmitter herein shown, but also to any other instruments in which microphonic contact is required. The contact e may be in one piece with or solidly attached to its carrier, if desired; but I very much prefer to have itloosely connected therewith, the connection being such that it is virtually suspended from the carrier with capacity for up-and-down movement with relation thereto. The preferred arrangement for this purpose is illustrated in the drawings. Into the lower end of the carrier arm or stem is screwed a short shank, h, of carbon, having a head, h, on its lower end. Upon this shank, is loosely mounted the carbon disk or button 0, which is formed with a hole, 6, for the passage of shank h, and with a recess, 6 on its under side to receive the head h. In order to prevent the disk from rotating on the shank the latter has a square or other equivalent form in cross-section, and the hole 6 is of corresponding shape, as indicated in Fig. 4:. In this way the disk 6 is loosely suspended from the carrier. The latter acts only to lift it, while its descent is due to gravity. Ifind that this arrangement is productive of most excellent results, and in practice is much to be pre ferred over a rigidly-connected contact-point.

I have indicated what I deem to be a good form of stationary contact, d, to operate in connection with the movable contact just dei scribed, but I do not desire to be nnderstooc as restricting myself to that special form.

The circuit-connections and the adjustments arein the transmitter shown in the drawings the same as those illustrated in the Letters Pateicl't Eerefnbforerefcrredgto. 7

Battery E, Fig. 5, having one pole groundrd is in circuit with the condenser F through wire 1, binding-post 0, wire 3, (leadingfromO to arm 0 front eontact-points, c 0, wires $4,; (the former extending between 0 and the upper end of carrier f, and the latter from f to center binding-post, B,) post B, and wire 2; and the condenser discharges to line through wire 2, post I3, wire 4, rear contact-points, e (2, wire 5, binding-post D, and line-wire 6. The normal adjustment of parts is such thatvthe points 0 0 have full contact,,while the points. d e have only partial or incomplete contact.

The principle of operation of the transmitter is fully set forth in the Letters Patent hereinbefore referred to, and requires no further explanation here. It is sufficient to say that when the instrument is used both "the circuit through which the battery charges the con denser and the circuit through which the condenser discharges to line are completed through the transmitter. The vibrations of the diaphragm result in alternately charging the con-' denser from the battery and discharging the condenser to line,.thus transmitting over the line-wire a series of electrical impulses with the effect of reproducing the voice at the receiving-station.

Having described my improvements and the best way now known to me of carrying the same into practical effect, I state in conclusion that I do not restrict myself to the mechanical details hereinbefore described, and shown in illustration of my invention; but

-What I claim, and desire to secure by Letters Patent, is

1. The combination, with the diaphragm, of a spring-acting carrier mounted on the dia IIO phragm, acontact-point connected or attached to said carrier, and a stirrup for controlling the movements of the carrier, substantially as and for the purpose hereinbefore set forth.

2. The combination, with the diaphragm, I15 the springacting carrier, and its contact-point, of a stirrup adjustable with relation to said carrier, substantially as and for the purposes hereinbefore set forth. a

3. The diaphragm, the bent spring-acting carrier, and its contact-point, in combination with a stationary contact-point to operate in connection with the carrier contact-point, and a stirrup which controls and directs the movement of the carrier to and from the stationary I25 contact-point, substantially as hereinbefore set forth.

at. The combination, with the diaphragm and the spring-acting carrier, of a contact disk or button loosely mounted on or suspended from said carrier, substantially as and for the purposes hereinbefore set forth.

zeases 1 s 5. The combination of the diaphragm, the I carrienstem f, secured thereto, and provided spring-acting carrier, the contact disk or button suspended from or looselymonnted on said carrier, the stirrup for controlling the move 5 ments of the carrier, and the stationary conraotpoint, substantially as and for the purposes hereinbefore set forth.

6. The combination of the diaphragm, the bent springaeting carrier, the contact disk or 10 button suspended from or loosely mounted on the lower vend of the same, so as to be capable of independent vertical movement without rotation, the carrier-controlling stirrup, and the stationary contact-point, substantially as and I 5 for the purposes hereinbefore set forth.

7. The combination of the diaphragm, the

with a slanting spring portion, f, intermediate between its upper horizontal and lower vertioal ends, the contact button or disk loosely mounted on the lower end of said carrier-stein, the controlling-stirrup 9, adapted to operate against or in connection with the spring portion f, and the stationary contact-point, for joint operation substantially as hereinhefore set forth.

In testimony where-of Ihave hereunto set my hand this 5th day of July, 1883. A

J AMES A. MALONEY. \Vitnesses:

E. A. DICK, J. WALTER BLANDFORD. 

